The present embodiments relate to an arrangement and a method for electrical detection of liquid samples using lateral flow assays.
Lateral flow assays are in widespread use in in-vitro diagnostics (IVD). Lateral flow assays are simple in terms of handling and very cost-effective. Disadvantages of lateral flow assays include a low sensitivity, a low multiplexity and a poor quantifiability of the results.
A good quantifiability may be achieved by optical, magnetic and electrical methods, but heretofore with very low multiplexity (e.g., simultaneous measurement at a plurality of spatially separate measurement points).
U.S. Pat. No. 6,896,778 discloses an arrangement in which, for a good multiplexity, gold electrodes are arranged above cutouts of an electrically insulating carrier as an array, and the cutouts are filled with membranes composed of a polymer/microfiber matrix material. The membranes are spatially separated from one another. The membranes are ion-selective, and not suitable, for example, for immunosensors in immunoassays.
With the use of capture antibodies in immunoassays, the capture antibodies are to be immobilized directly on the gold electrodes or sensors. In an arrangement analogous to the laminated arrangement of a carrier including insulator layers and gold electrodes that is described in U.S. Pat. No. 6,896,778, where the gold electrodes are arranged above cutouts in the insulator layers in array form, a small cavity in each case arises above the gold electrodes through the surrounding insulator layer. When liquid is applied directly or via a lateral flow paper as a membrane above the arrangement, air bubbles arise in the region of the cavities and during a measurement, lead to a failure of the respective electrodes with air inclusions.